Pro Tools Mix Bus Chain: The Stock Plugins to Mix Into, With Settings (and the Master Fader Catch)

The short answer: a Pro Tools mix bus chain is two stock plugins and a meter on the Master Fader, in this order: EQ III (7-band) for a gentle subsonic cut and an input trim, Dyn3 Compressor/Limiter at 2:1 with 1 to 2 dB of gain reduction, and a meter last. Leave the Master Fader at 0 dB, because its inserts are post-fader: unlike every other Pro Tools track, the fader comes before the plugins. If you'll automate fades, build the same chain on a stereo Aux mix bus instead. Put it on early and mix into it. Keep Maxim, Pro Limiter and dither off until the master, and bounce with peaks around -6 to -3 dBFS. A mix bus chain glues the mix while you're still making decisions. It isn't a mastering chain, and it shouldn't try to make the track loud.

Mixing into a light bus chain, then mastering as a separate step, is how I work on my own releases (Sony, Universal, Ultra, Dim Mak, 50M+ streams). This is the stock Pro Tools version; the Ableton mix bus chain, the Logic Pro mix bus chain and the FL Studio mix bus chain do the same job in those DAWs. There's no Pro Tools build of my mastering chain, but two of them run inside Pro Tools, disclosed at the end.

First: the Master Fader is post-fader

On audio, instrument and Aux tracks, Pro Tools inserts are pre-fader: moving the fader doesn't change what a plugin hears. Master Fader inserts are the exception. They're post-fader, so dither placed there always processes the final level, fades included. Master Fader tracks also have no sends and no pan controls.

For a bus compressor, that means every Master Fader move changes how hard the compressor works. Pull the fader down 3 dB and you get less compression; automate a fade-out and the compressor eases off as the song fades. Two clean ways to handle it:

• Master Fader route. Put the chain on the Master Fader's inserts and leave the fader at 0 dB. Simple, and fine if you don't automate the master.
• Aux route. Send every track to a stereo bus, put the chain on a stereo Aux Input fed by that bus, and send the Aux to your main output, which the Master Fader controls. The Aux's inserts are pre-fader, so fades on the Master Fader happen after the chain. It's a common Pro Tools setup, and the Aux's pan knobs give you a stock mono check.

The chain and the settings below are the same either way.

Mix bus chain vs mastering chain

Both chains can live at the end of the session, but they have different jobs at different times.

If you've read what a mastering chain is, this is its little sibling: the same tools, at a fraction of the amount, doing a different job.

The chain, in order (settings chart)

Why Dyn3 and not BF-76? BF-76 is a great compressor, but it's modeled on the 1176: Avid's plug-in guide puts its attack between 0.4 and 5.7 ms, and its ratios start at 4:1. It grabs transients instead of letting them through, so it belongs on the drum group or the vocal; the Pro Tools vocal chain uses it that way. If your tier includes Avid's Impact, a console-style bus compressor, it's the closer match for this slot: 2:1 (its lowest fixed ratio), attack at 10 or 30 ms (30 ms is its slowest), release on Auto, and the same 1 to 2 dB of reduction.

Avid's own tip for Reel Tape Saturation is to use it on a Master Fader for tape-style compression on a mix; its Hi Output formula is the subtler of the two, per Avid's guide. Keep it low, or leave saturation for the mastering stage.

EQ III, the Dyn3 plugins and BF-76 have been part of Pro Tools for years, but the bundled set has shifted across tiers (Intro, Artist, Studio, Ultimate) and releases; Impact, Reel Tape Saturation and Avid's Pro series plugins aren't in every tier. Check your plugin menu, and treat the plugin window and Avid's Audio Plug-Ins Guide as the authority on control names.

How to set it up

1. Pick the route. Master Fader with the fader at 0 dB, or the Aux route: create a stereo Aux Input, set its input to a stereo bus (name it Mix Bus), set every track's output to that bus, and set the Aux's output to your main output.
2. Get a static balance first. Faders and pans only, no bus processing. If the song doesn't work as a rough balance, a bus chain won't save it. The order of operations is in how to mix a song.
3. Gain stage the channels. Pull track levels down so the mix peaks around -6 dBFS with everything playing. Gain staging explains why.
4. Load the plugins in order. EQ III (7-band), Dyn3 Compressor/Limiter, Reel Tape Saturation if you use it, then the meter. Save the track as a track preset (right-click the track name and choose Save Track Preset in recent versions), or keep it in a session template so every mix starts here.
5. Set the compressor on the loudest section. Loop the chorus or drop, pull the threshold down to 1 to 2 dB on the gain reduction meter, match Gain to the bypassed level, and toggle bypass to compare. If you can clearly hear it working, back off.
6. Mix into it. From here on, every fader move happens through the glue, so the balance you make is the balance you'll hear after the bus compressor. This is the reason it goes on early: adding bus compression at the end changes a balance you already signed off.
7. Check mono and references regularly. On the Aux route, turn both of the Aux's pan knobs to center to fold the mix to mono, then back to hard left and right. The Master Fader has no pan, so on that route put the free Ozone Imager last at Width -100%, which removes the side channel, and bypass it afterward. Compare against a commercial track at matched loudness; how to use reference tracks shows the loudness-matching step.

What not to put on the mix bus

• Maxim, Pro Limiter, or Dyn3 pushed to limiting. A limiter at the end of the mix makes everything sound louder and better for a minute and hides balance problems. If you want to preview loudness, put one last and bypass it before you bounce.
• BF-76 on the whole mix. Fast FET compression on the full mix flattens the transients you're trying to keep. Use it a level down.
• Heavy multiband. Pro Multiband Dynamics (in the tiers that include it) on the whole mix flattens the dynamics mastering needs. Multiband control belongs on single elements or at the mastering stage.
• Dither. POW-r Dither belongs on the final master when it's reduced to a lower bit depth, once. Your mix bounce stays at 24-bit or 32-bit float with no dither; what dithering is explains why.
• Big EQ moves. A 3 dB high shelf at the end of the mix is a sign the hats, vocal, or synths need EQ on their own tracks.
• Width boosts. Widening the whole mix with AIR Stereo Width makes the stereo image the last thing you can fix, and it's the first thing to collapse on club and phone speakers.

Group buses do the heavy lifting

A light mix bus chain works because most of the control happens a level down. Route the drums to their own stereo Aux and give it BF-76 or Dyn3 (often a few dB more reduction than the mix bus), add punch with a transient shaper if you have one (compared in the best transient shaper plugins), and run the lead through a proper vocal chain (the Pro Tools vocal chain uses stock plugins too). That leaves the mix bus with only one job: gluing parts that already work. The 808 and the kick need their own relationship sorted first, covered in how to mix 808 and kick.

Bouncing the mix for mastering

Open Bounce Mix (File > Bounce Mix; called Bounce to Disk in older versions), choose your main output as the source, and bounce a WAV, interleaved, at 24-bit or 32-bit float at the session's sample rate, with no dither. Keep the EQ and compressor on if you mixed into them, since the glue is part of the sound you approved, but make sure no limiter, loudness tool or dither is left in the path, the mono check is bypassed, and the Master Fader is at 0 dB. Peaks should land around -6 to -3 dBFS. If your mastering engineer asks for no master bus processing at all (my own stereo mastering intake does), bounce a version with the chain bypassed too. The full checklist is in how to prep a mix for mastering, and what is headroom explains the numbers.

Then the master

Once the mix is bounced, the mastering chain takes over in a fresh session or on the bounced file: cleanup EQ, glue, peak control, width and a limiter, each doing a small job. How to master a song walks through the stages, and the free Youlean Loudness Meter reads the result.

There's no Pro Tools stock build of my own mastering chain. Two of my chains run inside Pro Tools instead: the Ultimate Master Chain for Waves runs through Waves StudioRack, and the Ultimate Master Chain for Ozone loads in any DAW that runs Ozone 9, 10, 11 or 12 (Standard or Advanced) as a plugin, Pro Tools included. The Waves stages are explained in the Waves mastering chain. I'm biased; mix into a light bus chain first with any tools, and any mastering chain will have more to work with.

Quick answers

What should be on the mix bus in Pro Tools? EQ III (7-band) with a 20 to 30 Hz high-pass, Dyn3 Compressor/Limiter at 2:1 with 1 to 2 dB of reduction, and a meter last, with the Master Fader at 0 dB. No limiting, no dither, no loudness tools.

Are Master Fader inserts pre-fader or post-fader in Pro Tools? Post-fader, unlike inserts on audio, instrument and Aux tracks. Moving the Master Fader changes what a bus compressor on it hears, so leave it at 0 dB, or build the chain on a stereo Aux mix bus that feeds the Master Fader.

What are good Dyn3 Compressor settings for the mix bus? Ratio 2:1, knee around 5 to 10 dB, attack 10 to 30 ms, release 100 to 300 ms timed to the groove, threshold set for 1 to 2 dB of reduction on the loudest section, Gain matched to bypass, and optionally the side-chain LF filter on High Pass around 60 to 100 Hz.

Should I put a limiter on the master fader while mixing in Pro Tools? Only as a loudness preview you bypass before bouncing. Mixing into a limiter hides balance problems and takes away the headroom mastering needs.